This STTR Phase I project will prove the concept for a low-cost, rapid system for detecting bacterial contamination in platelet concentrates, in minutes and not days, with cost/performance equal to accepted testing methodologies. Though the US has one of the safest blood supplies in the world, significant danger exists from the transfusion of blood products contaminated with pathogenic bacteria. Bacterial infection represents the most dangerous transfusion-related risk in the US other than human error. Blood banks incubate platelet cultures for 2 days for bacterial testing. Since platelet units have a shelf life of 5 days, this 2- day reduction in shelf life has a harsh impact on the supply. The proposed solution will extend platelet lifetime by more than 30%, as well as enable the release of fresher platelets, which are safer and more effective than older platelets. The objective of this proposed R&D effort is to build and test a proof-of-concept system and develop a staining method for the detection of bacteria in platelet concentrate units. The proposed proprietary method is called Fountain Flow" Cytometry. This method is based on a system in which a stream of solution containing the microorganisms, labeled with fluorescent probes, is illuminated with an LED and the fluorescence is detected with a digital camera. The use of low-cost commercial digital cameras and LEDs makes this device economically attractive when compared to alternatives. The proposed research will test alternative dye combinations with a system designed to detect bacteria spiked into apheresis platelets against a background of red and white blood cells. The anticipated result is an alternative to more expensive, less sensitive, and slower detection systems. Fountain Flow" will allow detection of platelet contamination at the sensitivity of automated culturing devices, but in ~10 minutes. The system can be automated and would potentially allow the examination of hundreds of platelet units per day. Tests will be performed on E. coli inoculated into human apheresis platelet units. Key performance criteria will be the method detection limit (MDL) for E. coli, total assay time, detection efficiency, and rate of false- positive detections. Our overall performance objectives to demonstrate commercial viability of the technique are an MDL of ~1 bacterium/ml (in a 10ml sample) with a detection efficiency >75% (bacteria detected/bacteria present) and a flow rate of >3.0 ml/minute. The key task in this project is to develop a combination of staining reagents that will achieve these objectives. This research will be performed by a team of scientists from SoftRay Inc. in colaboration with its University of Wyoming STTR partner, a transfusion medicine consultant (Bonfils Blood Center, Denver), and a clinical microbiologist (Cleveland Clinic). PUBLIC HEALTH RELEVANCE: Approximately four million units of platelet concentrates are transfused in the United States annually, with an estimated one in one thousand to one in three thousand units contaminated with potentially pathogenic bacteria. Blood contaminated by bacteria now represents the most dangerous transfusion related risk in the US other than human error. This project proposes a system that will provide for lower-cost, more timely and more sensitive detection of bacterial contamination, providing for a safer blood platelet supply for transfusion.